The present disclosure relates to electric motors and generators or electrical power generating motors. In particular, the present disclosure relates to a sensor or sensorless brushless DC motor configured to generate AC electrical output while operating as a motor. Accordingly, the novel characteristics of the present disclosure include having a dual purpose stator assembly for producing torque in the rotor and for generating electrical energy output for load consumption. Thus, the embodiment offers a novel means for energy generation in BLDC motors. Further, its novel structural design as demonstrated by a prototype of a practical embodiment of the present disclosure allows it to achieve an efficiency level of 90-95%. This amount is greater than the conventional motor-generator (MG) set which operates on a 70% to 80% efficiency range. In addition, its dual functionality also allows it to effectively serve as powertrain in electric vehicles, while also adding significant advantages and capacity to extend the vehicles' drive range.
Conventional brushless DC motors are making significant contributions to the field of electric motor technologies. To generate torque, commutation methods of BLDC motors are accomplished through electromagnetic excitation by energizing the stator winding assembly using specific sequencing and algorithms. Rotor position sensing and commutation sequencing for torque generation are accomplished by the use of magnetic Hall Effect sensors and back electromotive force (BEMF) zero-crossing signals. BLDC motor technologies eliminate dangerous sparks, frictions, wear and tear that are the commonly known characteristics of the conventional brushed DC motors. Without brushes, the speed, durability, efficiency, and overall operations of BLDC motors are thus enhanced.
BLDC motors are also playing a strong and positive role in our environmental challenges caused by fossil fuels and combustion engines. Today, more and more electric vehicles are using BLDC motors as a powertrain, thus assisting in reducing fossil fuel consumption in the area of transportation. Integrated with advanced drivetrain and rechargeable batteries, electric vehicles have reached an impressive technological milestone of 140 to 240 miles per charge or drive range. BLDC motors are increasingly becoming more and more an integral part of this success.
However, despite their amazing capabilities and contributions, a deeper examination of their operating features reveals that their maximum potential has yet to be fully realized. Examining the relationship between the magnetic field of the permanent magnet rotor and the stator winding assembly during the motor's torque generation process reveals a foundation that is ripe for generating electrical energy while concurrently operating as a motor. For instance, while the motor is in active motoring function, as a byproduct of the energy expended to produce torque in the rotor, it also generates electrical energy known as back electromotive force (back—EMF). Upon being generated, this electrical energy or back-EMF travels in the opposite direction and opposes the supply voltages.
Nevertheless, electrical energy or EMF is being generated because all of the three fundamental conditions for how a voltage can be created exist while the motor is being driven. The first of the conditions is the presence of a magnetic field of the permanent magnet rotor. The second condition is the magnetic field being in motion, and the third, conductor or coil windings. The existence of these conditions is significant to the development of the present disclosure, especially the second aforementioned condition. For example, in order for the rotating magnetic field to exist in a conventional power generator, a separate prime moving force is often required to rotate the magnetic fields necessary to create electrical energy through the generator's stator windings. The prime moving force is usually furnished by a combustion engine, a turbine, or an electric motor. However, in the case of the BLDC motors, the supply energy input not only produces torque in the motor, it also brings into existence a condition ripe for electrical energy generation: a rotating magnetic field. Accordingly, by adding another segment of the third fundamental condition (a conductor or coil windings) and placing them in close vicinity relative to the motion of the rotating magnetic field, EMF or electrical energy can be generated.
As presented above, the maximum potential of the conventional BLDC motors has yet to be recognized or fulfilled. Thus it is desirable to fully utilize their potentials. By applying the principles of electromagnetic induction, and by placing a designated segment of coil windings arrangement relative to the motion of the rotor's magnetic field, the present disclosure provides an additional means for a BLDC motor to generate electrical energy while simultaneously operating as a motor. In accordance with the present disclosure, the generated electrical energy can then be harnessed, consumed immediately or be stored for later use that otherwise would have been wasted.